Deep Venous Thrombosis in Surgical Intensive Care Unit: Prevalence and Risk Factors

Critically ill patients are at high risk for developing venous thromboembolism. The objective of this study was to determine the prevalence of, and risk factors for, lower extremity deep vein thrombosis (DVT) among critically ill surgical patients in Thailand. Materials and Methods: Patients older than 15 years who were admitted to a surgical intensive care unit (ICU) of a tertiary care hospital were enrolled. Bilateral lower extremity compression Doppler ultrasonographic examination was performed to detect DVT within 14 days of ICU admission. Demographic data, primary disease, operative intervention, co-morbidities, acute physiology and chronic health evaluation (APACHE) II score and the length of ICU stay were tested for association with the presence of DVT. Results: Among the 190 first-time admitted ICU patients with a mean APACHE II score of 9.2 ± 6.0 (range, 0–29), 20 patients had DVT (prevalence of 10.5%). Thromboprophylaxis was not given to any patient. The only independent and significant risk factor for DVT was a longer ICU stay. Age, sex, APACHE II score, presence of comorbidities and operative intervention were not associated with the presence of DVT. Conclusion: The prevalence of DVT in critically ill patients in a Thai surgical ICU was approximately 10.5%. Further research is needed to evaluate the risks and benefits of venous thromboprophylaxis in Thai patients

Reconstitution of the Mia40-Erv1 Oxidative Folding Pathway for the Small Tim Proteins

Mia40 and Erv1 execute a disulfide relay to import the small Tim proteins into the mitochondrial intermembrane space. Here, we have reconstituted the oxidative folding pathway in vitro with Tim13 as a substrate and determined the midpoint potentials of Mia40 and Tim13. Specifically, Mia40 served as a direct oxidant of Tim13, and Erv1 was required to reoxidize Mia40. During oxidation, four electrons were transferred from Tim13 with the insertion of two disulfide bonds in succession. The extent of Tim13 oxidation was directly dependent on Mia40 concentration and independent of Erv1 concentration. Characterization of the midpoint potentials showed that electrons flowed from Tim13 with a more negative midpoint potential of −310 mV via Mia40 with an intermediate midpoint potential of −290 mV to the C130-C133 pair of Erv1 with a positive midpoint potential of −150 mV. Intermediary complexes between Tim13-Mia40 and Mia40-Erv1 were trapped. Last, mutating C133 of the catalytic C130-C133 pair or C30 of the shuttle C30-C33 pair in Erv1 abolished oxidation of Tim13, whereas mutating the cysteines in the redox-active CPC motif, but not the structural disulfide linkages of the CX9C motif of Mia40, prevented Tim13 oxidation. Thus, we demonstrate that Mia40, Erv1, and oxygen are the minimal machinery for Tim13 oxidation